CODEWITHSUNDEEP
c++qtdata-structuresstructqbytearray
user4000670
user4000670

Reputation:

Qt-how to convert a QByteArray to struct

I need to convert a QByteArray to structure. I have a structure like this: 

   struct mavlink_attitude_t
      {
          /// <summary> Timestamp (milliseconds since system boot) </summary>
            quint32 time_boot_ms;
              /// <summary> Roll angle (rad, -pi..+pi) </summary>
            float roll;
              /// <summary> Pitch angle (rad, -pi..+pi) </summary>
            float pitch;
              /// <summary> Yaw angle (rad, -pi..+pi) </summary>
            float yaw;
              /// <summary> Roll angular speed (rad/s) </summary>
            float rollspeed;
              /// <summary> Pitch angular speed (rad/s) </summary>
            float pitchspeed;
              /// <summary> Yaw angular speed (rad/s) </summary>
            float yawspeed;

      };

and I have a QbyteArray comes from the serial port. I already used union but I think it can't be used for QByteArray. Is there any other way? an example can really help.

Upvotes: 3

Views: 9943

Answers (2)

Phiber
Phiber

Reputation: 1103

The accepted response could not work. .data() is null terminated.
You have floats and ints, use shift left.
Example: 

mavlink_attitude_t.time_boot_ms = (bytearray.at(0) & 0xFFFF)      |
                                  (bytearray.at(1) & 0xFFFF) << 8 |
                                  (bytearray.at(2) & 0xFFFF) << 16|
                                  (bytearray.at(3) & 0xFFFF) << 24

if you use Little endian, inverse the indexs.

Upvotes: 1

yandreiy
yandreiy

Reputation: 191

You can cast it:

QByteArray arr;
mavlink_attitude_t* m = reinterpret_cast<mavlink_attitude_t*>(arr.data());

Upvotes: 4

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